Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
Now that antibiotic rotation has become a popular way for hog producers to cut drug costs in half without compromising on herd health or efficiency, a few noted swine specialists are challenging their producers to take this program one step further. Instead of feeding grower-finishers a low-cost production antibiotic for three-weeks and a therapeutic additive for one week, they suggest keeping the production antibiotic in the feed from 50 pounds to market weight and rotating to therapeutic additives only as needed.
"News Releases: Veterinarians Urge Hog Producers to Rethink Antibiotic Rotation,"
Iowa State University Veterinarian: Vol. 52
, Article 16.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol52/iss1/16